Acid Reflux Linked to Sleep Apnea

Medical researchers have long suspected a relationship between acid reflux and obstructive sleep apnea. Both of these conditions can seriously reduce a patient's quality of life. Now, a team of Canadian researchers have shown significant relationships between laryngopharyngeal reflux and sleep apnea.

Laryngopharyngeal reflux, or LPR, is the backflow of stomach contents up the esophagus and into the upper airway, whereas GERD includes backflow only into the esophagus. The refluxed stomach contents (refluxate) are mostly composed of acid and activated pepsin, a proteolytic enzyme needed to digest food in the stomach. The damage from this LPR can be extensive with symptoms including

altered voice

throat clearing

vocal fatigue

cough

Laryngopharyngeal reflux has been linked to more substantial illnesses including laryngospasm, tightening of the larynx, and glottic carcinoma.

LPR is common in the North American adult population, estimated to affect up to 35% of the population 40 years or older.

Obstructive sleep apnea (OSA) affects 4% to 9% of men and 1% to 4% of women. The researchers identified airway inflammation, an impairment in the oropharynx (pharynx posterior to the mouth), velopharynx (soft palate), and larynx (voice box) of OSA patients, using endoscopic sensory testing. Correlations between the level of laryngeal impairment and apnea severity strongly suggest a link between the conditions.

Patients with sleep complaints but no heartburn symptoms suffered episodes of nighttime acid reflux according to research presented at the 70th Annual Scientific Meeting of the American College of Gastroenterology. In a separate study, researchers found that symptoms of gastroesophageal reflux (GER) are common and frequently severe in patients with obstructive sleep apnea.

Patients with gastroesophageal reflux often report poor sleep, waking at night because of acid reflux. Some individuals who have respiratory problems exacerbated by acid reflux may frequently be without symptoms of heartburn. In a recent study 81 patients with documented sleep complaints at least three nights per week underwent polysomnographic sleep evaluations. 26 percent had acid reflux. Of those who suffered with reflux, 94 percent of the recorded reflux events were at least briefly awakened.

"These are patients without significant heartburn symptoms, who are experiencing acid reflux during sleep," explained William C. Orr, Ph.D. of Lynn Health Science Institute in Oklahoma City. "'Silent reflux' may be the cause of sleep disturbances in patients with unexplained sleep disorders."

In another study on GERD and sleep by researchers at Duke University Medical Center, GER symptoms were common and frequently severe in 168 patients undergoing sleep studies who reported symptoms consistent with sleep apnea. These patients had frequent daytime and nighttime heartburn symptoms. Those with sleep apnea reported much lower quality of life on a self-administered questionnaire. Those patients with sleep apnea who also reported moderate to severe nighttime GER reported even worse quality of life.

"All patients with sleep apnea should be evaluated for gastroesophageal reflux," said J. Barry O'Connor, M.D., of Duke University Medical Center, one of the investigators.